In moderate climate zones, utility meters are located in subsurface enclosures in areas near residences or other dwellings. Such enclosures are referred to as "pits." An example of such enclosure is illustrated in Haase et al., U.S. Pat. No. 1,781,280.
In Edwards et al., EPO Publication No. 0 252 184, meter data is transmitted from a utility meter in an underground pit to an in-ground electronic coupling circuit and then to an electronic collection unit carried by a meter reading person. Scuilli, U.S. Pat. No. 4,758,836, shows an electronic metering unit which uses the inductive coupling method of the metering unit of Edwards et al.
Besides inductive coupling systems, radio frequency transponder systems have also been known. Examples are illustrated and described in Cerny et al., U.S. Pat. No. 5,298,894, issued Mar. 29, 1994, and assigned to the assignee of the present invention. In these systems, a receiver/transmitter, and an associated antenna are enclosed in one or more sealed enclosures which are located in a larger pit for the water meter. When the transponder is interrogated by a signal, it returns a radio signal to a collection unit, either hand-held or carried in a vehicle, where the radio signal can then be decoded to extract the meter data.
A primary issue concerning all remote meter systems, whether used in pit installations or elsewhere, is their resistance to weather, and to submersion in the event that the pit fills with water. Therefore, a primary object of the invention is to provide a device that is resistant to environmental conditions in its operating environment.
Typically, the data storage device is powered by one or more batteries, which must also be contained in a sealed enclosure. For an example of a prior battery assembly, please refer to Karsten et al., U.S. Pat. No. 5,476,731, assigned to the assignee of the present invention.
Therefore, another object of the invention is to provide for battery replacement in the field without adversely affecting the environmental protection of the electronics in the assembly.
As with other electronic devices, there is also a desire to make the devices smaller in size, lower in the cost of manufacture, and easier to service in the field.